Name a physical quantity that remains constant in a uniform circular motion(A) Velocity (B) Acceleration(C) Momentum (D) Angular speed

In uniform circular motion, the object moves along a circular path with constant speed. Let's analyze each option:
• (A) Velocity: The velocity of an object in uniform circular motion changes constantly because the direction of motion is always changing, even though the magnitude (speed) remains constant. So, velocity does not remain constant.
• (B) Acceleration: The acceleration in uniform circular motion is always directed towards the center of the circle (centripetal acceleration), but its magnitude is constant. However, the direction of acceleration is constantly changing as the object moves around the circle. So, acceleration does not remain constant in terms of direction.
• (C) Momentum: Momentum is the product of mass and velocity. Since the velocity changes direction continuously in circular motion, the momentum also changes continuously. Thus, momentum is not constant.
• (D) Angular speed: Angular speed (or angular velocity) is the rate at which the object sweeps out an angle as it moves along the circular path. In uniform circular motion, the angular speed is constant because the object covers equal angles in equal time intervals.
Final Answer:
The physical quantity that remains constant in uniform circular motion is (D) Angular speed.